Category: Internet

Having “do we need ULA” blogologs with Ed Horley is great … and the best part of them is that we’re both right (aka: It Depends). OK, let’s try to quantify that last part.

A good friend of mine sent me an interesting question:

When I configure mpls ip on an interface, will all packets on that interface be labeled, or just the MPLS/VPN packets received through VRFs? I always assumed that stuff in the global routing table just got forwarded as IP packets without any labels.

Well, that’s not how MPLS works (at least not in its default incarnation on Cisco IOS).

You did read my blog post on ThousandEyes, didn’t you? What I forgot to mention was that they have this cool API that allows you to extract measurement data (including BGP topology) from their system. Can we do something cool with that?

A group of researches presented an “interesting” result @ IETF 87: migrating from IBGP full mesh to IBGP reflectors can introduce temporary forwarding loops. OMG, really?

Don’t panic, the world is not about to become a Vogon hyperspace bypass. Let’s put their results in perspective.

Andrew sent me the following question: “I'm pushing to start a conversation about IPv6 in my organization, but meanwhile I've no RFC 1918 space left. What's your take on 100.64.0.0/10 - it's seems like this is available for RFC 1918 purposes, even if not intentionally?”

Short answer: Don’t even think about that!

In the TCP, HTTP and SPDY webinar I described the web application performance roadblocks caused by TCP and HTTP and HTTP improvements that remove most of them. Google went a step further and created SPDY, a totally redesigned HTTP. What is SPDY? Is it really the final solution? How much does it help? Hopefully you’ll find answers to some of these questions in the last part of the webinar.

The SDN industry probably considers me an old and grumpy naysayer (and I’m positive Mrs Y has a special place in their hearts after her recent blog post), so I tried really hard to find a real-life example where OpenFlow could be used to solve mid-market innovator’s dilemma to balance my usual OpenFlow and SDN presentation.

More than four years ago one of my friends wrote about uselessness of UMTS connections (the page has decayed into digital wasteland in the meantime) for inter-router backup links and although I got numerous comments trying to explain the issues I never found a good explanation that a simplistic networking engineer like me could understand.

Ilya Grigorik fixed that. His Breaking the 1000 msec Time-to-Glass Mobile Barrier talk has some real-world statistics, and a fantastic description of how 3G/4G networks work and what causes the enormous latencies. His High Performance Browser Networking book has even more details. Enjoy!

In the first part of the TCP, HTTP and SPDY webinar I explained why TCP and HTTP impact the end-to-end web application performance. In the second section of the webinar, we did a deep dive into the actual TCP and HTTP mechanisms that increase end-to-end latency (3-way handshake, initial congestion window, request/response nature of HTTP).

The responses to my What did you do to get rid of manual VLAN provisioning post were easy to predict: a few people sharing their best practices (thank you!), few musings on the future of SDN/networking, and the ubiquitous anonymous rant against stubbornness and stupidity of networking engineers and their OPEX.

I know one should never feed anonymous trolls, but this morsel is simply too juicy to pass, so here it is – let’s see what makes networking so complex.